Many communication systems exist today to deliver media content over networks, such as the Internet, to client computers subject to a Quality of Service (QoS) requirement. There are different types of QoS requirements. Some communication systems use dropped or lost packets as a measure of QoS. In other systems, QoS is a function of visual fidelity, such as resolution and frame rate. Additionally, QoS can involve audio quality. Both visual fidelity and audio quality are usually controlled by the amount of compression of the source data and the bit rate at which the source data can be delivered. Typically, compression and bit rate are inversely related to QoS. For instance, high compression generally correlates with low QoS.
QoS is changing as wireless and wired devices become smaller and more prevalent. What was once acceptable for a user using a desktop computer might not be suitable for the same user using a Personal Digital Assistant (PDA), as the PDA might not be able to support large video or audio files. In fact, a user using a PDA could have a lower QoS requirement, with no perceived harm, than when the user uses a desktop computer. Consequently, QoS requirements are in a state of flux.
Thus, there is a need to provide methods and apparatus suitable for dealing with changes in QoS in communication systems.